Filter



Sept. 22, 1931.

C. B. FOLEY Patented Sept. 22, 1931 UNITED STATES PATENT-OFFICE CHARLES 1B. FOLEY, OF FORT WAYNE, INDIANA, ASSIGNOR TO S. F. BOWSER 8c COMPANY, IN'G, 01' FORT WAYNE, INDIANA, A CORPORATION OF INDIANA mama Application filed August 2, 1928. Serial No. 296,908.

the capacity of the filter by preventing the grooves or passageways from becoming re-' 1satricted by the adjacent spaced-apart crossars. V v

Another object of the invention is the rovision of a porous metal disc laminated lter formed by the winding at thesame time of a plurality of tape to enable thinner metal tape to 'be used than can be employed when a sin-. gle tape is wound into the form of a disc filter.

Another object of the invention is the provision of a porous disc filter formed by wmding in superimposed relation one or more pairs of metal ribbons or tapes'having the spacectapart' transverse cross-bars on one tape and arranged in diagonal relation to said tape and in criss-crossed relation to the diagonally extending spaced-apart cross-bars on the next adjacent tape.

hereinafter, the novel features. and combinations being set forth in the appended claims. c

In the accompanyin drawings: Fig. 1 represents afilter element embodying my invention;

Fig. 2 is an enlarged fragmentary section of one of the tapes or ribbons shown in Fig. 1

Fig. 3 shows ,sectionsqof tapesor ribbons illustrating the criss-crossed relation of the spaced-apart ridges or cross-bars on the pair of tapes when wound into the form of a po-,

rous disc as shown in Fig. 1;

Fig. 4 is an enlarged view of a portion of the disc filter to illustrate the arrangement of the spaced-apart ridges or cross-bars and the passageways afforded by'the winding of the grooved metal tapes, into the form of a disc filter; and

Fig. 5 illustrates mechanism for supporttransversely.

Other objects of the invention will appear ing the disc filters in multiple for filtering liquid passing through the container shown.

In Fig. 1 I have shown a filter element consisting of two thin metal ribbons or tapes 5 and,6, so constructed and wound as to form a flat porous disc 7 having a thickness equal to the width of the tape. The pair of ribbons or tapes may be wound in a groove 8 of a hub.9. The tape 5 may have its inner end inserted in a slot 10 extending transversely of the groove 8. In a similar manner the inner end of the tape'6 may be inserted into a similar slot 11 in the hub 9.

In Fig. 2 I have shown an enlarged portion of the tape 6 to illustrate that the depressions 12 in the tape are wider than the ridges, barriers or cross-bars 13. The grooves 12 and cross-bars 13 are arrangeddiagonally of the tape 6. In a similar manner, the grooves 14 and cross-bars 15 of the tape 5 are arranged to extend diagonally across the tape but in the opposite direction In order to make the area of the .combined passageways extending across from one flat face of the disc filter to the other as large as possible while maintaining the desired cross-sectional area of each pas- Sageway, very thin ribbon is preferable and is for that reason quite flexible.

-When a single tape or ribbon provided with spaced-apart transverse grooves and ridges is wound tightly into the form of a discthe tendency is for the pressure from the cross-bars or ridges to bend the smooth body between the cross-bars of the next adjacent tape into the grooves or transverse passageways of the filter thereby dimlmshing the cross-sectional area of the passageways. It has therefore been found necessary, in order to retain the predetermined cross-sectional area of the passageways, to widen the ridges or cross-bars relative to the rooves when a single tape is wound upon itself, but this decreases the cross-sectional area on account of the widening of such cross-bars. By means of my improvement the depressions or grooves 12 may be wider thanthe. cross-bars as shown in Fig. 2. In other words, by providing a pair of tapes or ribbons with the transverse diagonal spaced-' 100.

apart grooves in relative criss-cross arrangement the cross-bars of one tape will'bear against the smooth surface of the other tape without any tendency of depressing the metal between cross-bars. This can readily be seen by referring to Fig. 3, where I have shown superposed sections of the tapes 5 and 6.

In .the drawings, the smooth sides of the tapes are shown wound to face toward the center of the disc. When the smooth bottom of the tape 6 is thus .wound over the outer grooved surface of the tape 5 the cross-bars 13 of the tape 6 occupy a criss-crossed relation with respect to the cross-bars 1d of the tape 5. l

The ribbons or tapes are preferably wound in pairs with the cross-bars side laid against the smooth side of the other of the pair. Fairs of tape may be wound with their smooth faces toward or away from the center of the disc, the winding shown inFig. 3 having the cross-bar faces of the ribbons away from the center of the disc. If desired, a plurality of pairs of tapes may he -wound simultaneously into the same disc, particularly when the tapes are very thin and require distribution of the pulls exerted during the winding operation.

As shown in Fig. 3, the cross-bars 13 extend across two bars 14, as illustrated at 16 and 17. The angularity of the cross-bars may be varied, but it is preferred to rovide direct passageways between the fiat faces of the disc and by having at least two points 16 and 17 of cross-over, there will be no tendency of thebars to press into the smooth surface backs of the grooves. By thus preventing the backs of the grooves from becoming indented by adjacent cross-bars .the grooves 12 may be made wide and the cross-bars comparatively narrow, thereby increasing the porosity of the disc filter by preserving the full cross-sectional area of each tubular passageway between the fiat faces of the disc, which tubular passageways extend from edge to edge ofthe laminations composed of the metal ribbons or tapes 5 and 6.

Fig. 4.- is an enlarged view of a portion of a disc filter. This view shows the metal tapes a great deal thicker than would be used in practice in order to show the passageways 12 and 15 more clearly, since these passageways are minute and approach capillary proportions. The metal tape is in reality very thin,preferably thinner than Bristol board drawing paper, and the depressions in the tape are small, shallow depressions made by compressing with a die wheel one of the smooth metal surfaces of each metal tape.

The cross-sectional area and the shape of the passageways may be varied in accordance with the nature, viscosity, etc., of the liquid to be filtered and with the nature of the impurities to be removed from the liquid. The width of the tape may also be varied, but it is preferable to use a comparatively narrow tape, the width and cross-section to be consistent with the strength of the disc filter and its diameter. A narrow m tape shortens the passageways and reduces thefriction of the liquid passing through the filter and therefore reduces the pressure necessary tooperatc the filter.

The tapes may he of copper or other material of sufiicient strength to permit tight winding of both tapes without undue distortion, compression or stretching of the metal itself. Since the channels are preferably formed by indentations or depressions in one surface, of each tape, the cross-bars are integral with the body of the tape in the form shown in the drawings.

While the thickness of the tape and the depth of the grooves may be varied according to conditions and the material to be filtered, it has been found satisfactory to filter certain kinds of oils by using copper ribbons or tapes one quarter of an inch in width and four-thousandths of an inch in thickness, with the depressions. or grooves from three-ten-thousandths to five-ten-thousandths of an inch in depth and each groove having a width of approximately one-sixteenth of an inch, leaving the separators or dividing ribs approximately one-thirty-second of an inch to one-siXty-fourth of an inch in width. That is to say, the cross sectional dimensions of each transverse groove was one-sixteenth of an inch wide and from three ten-thousandths to five-ten-thousandths of an inch in depth and the cross-sectional dimensions of each cross-bar was one-thirtysecond of an inch to one-sixty-fourth of an inch by from three-ten-thousandths' of an inch to five-ten-thousandths of an inch, in

a double ribbon wound copper disc filter found to be practical for efficiently removing impurities from certain kinds of oils such as oils used for transformers in electrically insulatin the same; it has also been found desirable and practical for filtering switch oils. It should be understood, however, that l donot wish to be limited to these particular dimensions and that they are set forth for illustrative purposes as to the practicability and utility of the disc filter when the through-put is increased by enlarging the width of the grooves.

It should also be understood that the depressions in the tape may be made in various ways, but it has been found to be satisfactory to prepare a roll or wheel with the the, tape. The degree of filtration may be regulated by regulating the sizes of the openings, passageways or grooves which are rolled into the tape as above described.

It is one of the purposes of this invention to use any shape of separator which will maintain uniform cross-sectional areas of passageways found in conjunction therewith and at the same time, when two tapes are wound together, will prevent the body of the tape or the separators from being compressed or forced into the underlying passageways thereby reducing the effective combined area of the passageways in the completed porous disc filter so formed. In my copending application Serial No. 379,087, filed July 18, 1929, for an Improvement in Filters, I have shown, described and claimed crescent-shaped cross-bars in criss-cross relation on a pair of filter ribbons wound into the form of a disc filter element.

It will also be evident that while I prefer to use tapes or ribbons with the separators integral therewith, such separators may be attached thereto while still maintaining freedom from passageway obstruction and while maintaining requisite strength for winding because by winding two or more tapes simultaneously, thinner tape may be used, the winding pull being distributed on the plurality of tapes while being wound, and the increased pull thus permitted, results in the winding of a much more compact disc filter than is possible when a single thin tape is wound into a disc.

In Fig. 5 I have shown two disc filtering units mounted in multiple and each with their flat faces in vertical planes The hubs 9, 9 are provided with ports 18, 18', which are adapted to register respectively with the ports 19, 19' when the filter units are assembled as shown in Fig. 5, on the pipe 20. This pipe 20 is screw-threaded at 21 to the outlet port 22, which is located at the .center of a fiat plate 23. The latter is detachably connected by means of the bolts 24 to the casing 25, which has an inlet port for the material to be filtered, at 26. y I

Each filter disc is mounted in a fiat cup 27, 27 7 the discs being soldered at their peripheries 28, 28, to annular recesses in the cups 27 and 27 so as to form chambers 29, 29 for the flow of the filtered liquid through the passageways 18, 19 and 18, 19 into the tube orplpe 20, as indicated by the arrows. The center of each flat cup 27, 27 is provided with a hub 30, 30', which fitsover the pipe 20, and by means of the hubs 30, 30' and 9, 9'

the filter units will be spaced apart as shown in Fig. 5. By means of the can 31 screwthreaded onto the right hand end of the pipe 20, the filter units are securely held in place.

The connection at 26 is shown screwthreaded in Fig. 5 for the connection of a pipe for leading the liquid under pressure into deposited caked impurities will themselves;

.act to filter the impurities of additional liquid flowing into the casing 25. Inasmuch as the filters are arranged in vertical position, such impurities as are not caked on the right hand faces of the filter elements may fall by gravity to the bottom of the casing 25 and be drained out from time to time by removing the screw threaded plug 32. Also at intervals the plate 23 maybe removed to gain access to the right hand faces of the filter elementsto remove the impurities caked thereon, thus restoring the filter to its original efiiciency.

It should be understood that by referring to tapes or ribbons, I have used the words interchangeably, meaning the same thing.

These tapes or ribbons are wound as tightly as is consistent with their strength. Multiple-ribbon may be wound more tightly than a single ribbon of the same dimensions.

When completed, the filter is very compactly wound, so super-tight, in fact, as to have the appearance of a solid disc or plaque of metal and when mounted on the hub 9 within the grasp of the periphery of the cup 27 by soldering or otherwise the metal gives the disc ample strength to withstand considerable pressure placed on the inlet faces of the disc by the pressure exerted on the liquid pumped into the casing 25 under pressure.

Obviously those skilled in the art could make various changes in the details and ar rangement of parts without departing from the spirit and scope of the invention defined by the claims hereto appended, and I wish therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an em-- bodiment of my invention, what I desire to have secured by Letters Patent of the United States is '1. A filter element comprising impermeable laminations with spaced-apart crossbars c riss-crossed relative to the adjacent laminations to form with smooth surfaces of next adjacent laminations criss-crossed channels extending from one face of the filter element to the other face thereof.

2. A filter element comprising a pair of metal ribbons wound to form a disc, eachribbon having a smooth surface on one side the other side being provided with spaced-apart cross-bars extending diagonally and transversely of the ribbons to form tubular passageways between the faces of the disc, the

a between the flat faces of the dis diagonal relation of the cross-bars on one ribbon of the pair being opposite to the diag-- onal relation of the cross-bars on the other ribbon of the pair.

3. A laminated filter comprising impermeable ribbon having thereon spaced-apart other face thereof when the filter ribbon is stacked in laminations very compactly and rigidly.

4. porous disc filter comprising a pair of narrow ribbons each having one side smooth and the other side provided with spaced grooves and crossbars thereon, each groove co-acting with the back of the next adjacent ribbon to form a channel extending entirely across the filter and open from end to end, the grooves being wider than the cross-bars and the pair of ribbons wound with the cross-bars spanning the backs of the grooves to prevent indenting of the backs of the grooves 5. A ribbon wound filter comprising spaced-apart cross-bars engaging a smooth ribbon surface, with the spaces betweenthe cross-bars wider than the cross-bars and serving as transverse channels extending entirel across the ribbon and open from end to en and means for preserving the cross-sectional area of the channels by criss-crossing the cross-bars of one ribbon with the grooves of the next a djacent ribbon to prevent bending of the ribbon into such channels.

6. A porous metal disc comprising a pair of thin metal ribbons wound tightly into a compact disc having fiat faces, the inner surfaces of the ribbons being smooth and the outer surfaces thereof being provided with spaced apart grooves or channels separated by narrower spaced-apart cross-bars arranged diagonally on one ribbon in one direction and diagonally on the other ribbon in the opposite direction to criss-cross the super-imposed position of the cross-bars and prevent them from indenting the smooth backs of the ribbons into the ooves when wound tightly into the form 0 such disc.

7. A porous metal disc. comprising a pair of vnarrow copper ribbons wound tightly into a compactmetal disc havin flat faces, the inner surfaces of the ribbons being smooth and the outer surfaces being provided with spaced-apart grooves se mated by spaced-apart cross bars dia onal y arranged in one direction on one ri bon and in the opposite direction on the other ribbon to- 8. A porous disc filter comprising a pair of narrow ribbons with spaced grooves and cross-bars thereon to form unobstructed pores between the faces of the filter, the cross-bars on each ribbon extending diagonally across one side of the same so as to make obtuse and acute angles at both edges of the ribbon the other side of the ribbon having a smooth surface, the grooves on each ribbon being wider than the cross-bars thereon and the ribbons being wound without indenting the backs of the grooves.

9. A filter comprising a pair of thin ribbons wound to form a disc, each ribbon being provided with spaced-apart cross-bars extending transversely of the ribbon on one sidethereof to form tubular passageways between the faces of the disc the othcr side of each ribbon having a smooth surface, the relation of the cross-bars on one ribbon of the pair being opposite to the relation of the cross-bars on the other ribbon of the pair.

10. A filter element comprising a pair of thin ribbons wound to form a disc, each ribbon being smooth on one side and on the other side being provided with spaced separators in transverse relation to the separators of the next adjacent ribbon, with the passageways uniform in cross-sectional area from one face of the disc to the other.

11. A porous disc filter comprising a pair of ribbons wound tightly into a compact mass, one surface of each ribbon being smooth and the opposite surface having spaced-apart grooves separated by spaced-apart cross-bars arranged in transverse relation relative to those on the next adjacent ribbon to prevent the cross-bars from indenting the backs of the ribbons into the grooves and thereby maintain the predetermined cross-sectional area of the tubular passagewaysbetween the faces of the disc filter.

12. A porous disc filter comprising a pair of thin ribbons wound tightly into a compact disc, one face of each ribbon being smooth and the other side provided with spaced-apart grooves separated by spaced-apart cross-bars arranged on one ribbon in transverse relation to the cross-bars on the next adjacent ribbon to criss-cross'the superimposed positions of the cross-bars and to prevent them from indenting the backs of the grooves of the next adjacent ribbon when wound tightly to form such disc, said cross-grooves being open from one side of the disc to the other side thereof.

13. A laminated filter comprising a plurality of ribbons each provided with a smooth surface on one side and on the other side with spaced-apart cross-bars to form when laminated spaced-apart cross-grooves of uniform cross-sectional area from one side of the filter to the other, the cross-bars of each-lamination being in transverse relation to the crossbars on the next adjacent lamination to prevent indentation of such grooves andmaintai n such uniform cross-sectional area thereof when the laminations are made very com- )act. l 14. A porous laminated ribbon filter, each ribbon lamination having one surface smooth and the other side provided with spaced-apart cross-bars narrower than the grooves formed thereby when the laminations are laid, and the cross-bars on one laminationbeing in criss-cross relation to the cross-bars on the next adjacent lamination.

'15. A porous disc filter having unobstructed passageways open from end to end between the faces of the filter and comprising a pair of uniformly continuous ribbons of relatively thin metal with spaced separators on one side of each ribbon resting against the smooth side of the. next adjacent ribbon to form such passageways each wider than each of said separators, the separators of one ribbon being in overlapping relation with the separators of the other ribbon to prevent indenting ofthe backs of the said-passageways. I

16. The method of assembling a disc laminated filter which consists in winding simultaneously a plurality of impermeable tapes each with raised diagonal separators on one surface thereof with the smooth surface of one tape against the separators of the next adj acent tape to form pores for the filter open from end to end between the faces thereof and in cries-cross relation with the pores between the next adjacent laminations, the pull for winding being distributed on the tapes.

In testimony whereof I have signed my name to this specification on this 28 day of June, A. D. 1928.

CLES B. FQLEY. 

